1. Technical Field
The present invention is directed towards a press stitcher transfer mechanism and, more particularly, towards a mechanism for conveying properly aligned folded signatures to a press stitcher.
2. Background Art
Mechanisms or conveyors for collecting and transporting signatures to a stitcher are well known in the art. Typically, these mechanisms are intended for use with a conventional reciprocating stitcher assembly, but the use of such stitcher assemblies has numerous drawbacks. For example, reciprocating stitcher assemblies are usually the limiting factor in the effort to quickly process signatures into completed products In addition, reciprocating stitcher assemblies have many moving parts causing them to break down relatively frequently, further limiting the ability to quickly process signatures. Illustrative of mechanisms for feeding signatures into a conventional reciprocating stitcher are those discussed in Macey U.S. Pat. No. 4,479,642 and Mowry et al. U.S. Pat. No. 4,641,825.
A significant increase in the speed at which signatures are processed may be achieved by using a rotary press stitcher. The use of a rotary press stitcher requires that the spine or fold of the signature be aligned perpendicular to the line of travel of the conveyor. Thus, if a rotary stitcher is to be used, the signature conveyor shown in Macey is unacceptable.
Stob U.S. Pat. No. 4,478,398 discloses a press stitcher conveyor which delivers signatures to a rotary press stitcher with the spine or fold aligned perpendicular to the direction of travel. Stob's press stitcher conveyor does, however, presents several serious drawbacks. For instance, Stob teaches the stitcher transport mechanism as being disposed vertically, but due to space constraints, the Stob configuration may be impractical for many installations. Stob also requires a shoe or guide to force the signatures to be pivoted 90.degree. into proper alignment for stitching. As will be apparent, this pivot step can jostle the stacked signatures under transport which could result in misaligned stitched signatures.
The present invention is directed toward overcoming one or more of the problems discussed above.